Continuous Delivery in Software Development

Continuous Delivery (CD) is the next step in the evolution of the software development process. It draws on Agile methodologies but surpasses them. CD is changing the way software is delivered and opening up a whole range of benefits, ranging from greater adaptability to more reliable products to improved customer experiences.

But what if continuous delivery means sacrificing quality for speed? Does it really lead to both higher responsiveness and higher reliability? Let’s find out if it really enables you to get better products to your customers more often.

List of the Content

• What is continuous delivery in software development?
• Continuous delivery benefits
• Continuous delivery vs continuous integration
• Continuous delivery vs continuous deployment
• How to implement continuous delivery in software development?
• Continuous delivery tools
• Conclusion

WHAT IS CONTINUOUS DELIVERY IN SOFTWARE DEVELOPMENT?

Continuous delivery is a software development approach allowing teams to release updates frequently, reliably, and with minimal effort. This approach focuses on creating a streamlined and automated process for building, testing, and deploying software, enabling development teams to respond quickly to changing requirements and customer feedback.

The traditional software development process involved long release cycles, often taking months or even years to deliver a new feature or functionality. This approach had several downsides, including a lack of flexibility and responsiveness, a high risk of bugs and errors, and a longer time-to-market. Continuous delivery solves these issues by automating the process of building, testing, and deploying software, allowing for faster and more reliable releases.

Continuous delivery involves several key practices, including continuous integration, automated testing, and deployment automation. Continuous integration involves integrating code changes into a central repository on a regular basis, enabling teams to catch errors early and ensure that the software is always in a stable state. Automated testing is a crucial part of continuous delivery, as it allows for fast and reliable testing of the software, reducing the risk of errors and bugs. Deployment automation enables teams to automate the process of releasing new software versions, reducing the time and effort required for deployment.

Continuous delivery also involves close collaboration between development, testing, and operations teams, as well as a strong focus on feedback and continuous improvement. By working together and continuously iterating on the software, teams can quickly respond to changes and improve the quality of the product over time.

The benefits of continuous delivery are significant. By releasing software updates more frequently, teams can respond more quickly to feedback and changes in the market, leading to a better user experience and increased customer satisfaction. The automated testing and deployment processes also reduce the risk of errors and bugs, improving the overall quality of the software. Finally, the continuous improvement cycle enables teams to learn from their mistakes and make incremental improvements to the software over time, leading to a more robust and stable product.

However, implementing continuous delivery can be challenging, as it requires significant changes to the development process and culture. Teams must be willing to embrace automation and collaboration and be open to continuous feedback and improvement. Additionally, the process of building and maintaining the necessary infrastructure and tools can be complex and time-consuming.

Therefore, continuous delivery is a powerful approach to software development that enables teams to release software updates quickly, reliably, and with minimal effort. By automating key processes and focusing on collaboration and continuous improvement, teams can create better software and respond more quickly to market and customer needs changes. While implementing continuous delivery can be challenging, the benefits make it a worthwhile investment for any software development team.

CONTINUOUS DELIVERY BENEFITS

The practices at the heart of continuous delivery in software development help us achieve several important benefits:

Lower costs

Any successful product or service will evolve significantly over the course of its lifetime. By investing in build, test, deployment, and environment automation, we substantially reduce the cost of making and delivering incremental changes by eliminating many of the fixed costs associated with the release process.

Low-risk releases

The primary goal of continuous delivery software is to make deployments painless, low-risk events that can be performed at any time on demand. By applying patterns such as blue-green deployments, it is relatively straightforward to achieve zero-downtime deployments that are undetectable to users.

Faster time to market

It’s not uncommon for the integration and test/fix phase of the traditional phased lifecycle to consume weeks or even months. When teams work together to automate the build and deployment, environment provisioning, and regression testing processes, developers can incorporate integration and regression testing into their daily work and completely remove these phases. We also avoid the large amounts of re-work that plague the phased approach.

Happier team

Peer-reviewed research has shown continuous software development makes releases less painful and reduces team burnout. Furthermore, when we release more frequently, teams can engage more actively with users, learn which ideas work and which don’t, and see first-hand the outcomes of the work they have done. By removing the low-value painful activities, we can focus on what we care about most—continuously delighting our users.

Better products

Continuous software development makes it economical to work in small batches. This means we can get feedback from users throughout the lifecycle based on working results. Techniques such as A/B testing enable us to take a hypothesis-driven approach to product development whereby we can test ideas with users before building out whole features. This means we can avoid the 2/3 of features we build that deliver zero or negative value to our businesses.

Higher quality

When developers have automated tools that discover regressions within minutes, teams are free to focus their effort on user research and higher-level testing activities such as exploratory testing, usability testing, and performance and security testing. By building a deployment pipeline, these activities can be performed continuously throughout the development process, ensuring quality is built into products and services from the beginning.

Better visibility and control

Continuous delivery provides greater visibility and control over the software delivery process, as teams can track and monitor changes, releases, and deployments in real-time. Also, it helps organizations meet compliance requirements more easily, as changes can be thoroughly tested and tracked, and deployments can be audited.

CONTINUOUS DELIVERY VS CONTINUOUS INTEGRATION

Continuous delivery and continuous integration are two related but distinct practices in modern software development. 

Continuous integration is a software development practice where developers regularly merge their code changes into a shared repository, and an automated build and test process verify each integration. CI aims to catch errors and conflicts early in the development process, so they can be addressed before they cause significant problems.

CI requires a robust testing and validation infrastructure to automate the build and test process. Whenever a developer makes a change to the code, it triggers the CI process, which includes compiling the code, running tests, and checking for errors. If any issues are identified, the developer is notified, and they can make the necessary changes to fix the issue. This helps to catch errors early in the development process, reducing the cost and effort required to fix them later on.

Continuous delivery builds on the foundation of CI by adding additional automation and tooling to the development process. Once the code is merged and tested successfully, it is packaged and prepared for deployment to production. The CD pipeline includes a set of automated tests and validation processes that ensure that the code is ready for release.

While continuous integration and continuous delivery share some similarities, there are some key differences between the two:

Purpose: The primary purpose of CI is to automate the build and test process of the software development cycle, providing early feedback to the developers when an issue arises. This allows developers to quickly identify and resolve issues, improving the quality and reliability of the codebase. In contrast, the main purpose of CD is to automate the deployment process and prepare the code for release to production. CD ensures that the code is production-ready and tested, making the deployment process more efficient and reliable.

Level of automation: CI is focused on automating the build and test process, allowing developers to integrate their changes into the main codebase frequently. This requires a robust testing and validation infrastructure to automate the build and test process. On the other hand, CD requires a higher degree of automation and tooling than CI, as it involves preparing the code for deployment to production and running additional tests and validation processes.

Decision-making process: In CI, the decision to merge the changes into the main codebase is made automatically by the system based on the successful completion of the build and test process. The decision to release the software to production, however, is made by the development team in CD. The CD pipeline prepares the code for release, but it’s up to the team to decide when to release the software, taking into consideration any business requirements or dependencies.

Focus on delivery: CI focuses on integrating the code changes as frequently as possible, making it easier to identify and resolve issues quickly. On the other hand, CD focuses on delivering the code to the end users in a controlled and efficient manner. It aims to reduce the time and effort required to deploy code to production, improving the overall delivery process.

As a result, CI and CD are both important practices in modern software development, but they serve different purposes. CI is focused on automating the build and test process and providing early feedback to the developers. In contrast, CD is focused on automating the deployment process and preparing the code for release to production. Both practices require a high degree of discipline, quality assurance, and team collaboration to succeed.

CONTINUOUS DELIVERY VS CONTINUOUS DEPLOYMENT

Continuous deployment is an extension of continuous delivery that takes automation to the next level by completely removing human intervention from the release process. Continuous deployment automatically releases the software into production as soon as it passes all necessary tests and validation processes.

This practice is useful for teams that need to deliver updates to their customers quickly and frequently, such as those in the e-commerce or mobile app industries. By removing the need for human intervention, CD helps to reduce the time-to-market and increase the frequency of software releases.

Continuous deployment can be risky if proper testing and quality assurance processes are not in place. It requires a high degree of confidence in the automated testing and validation processes to ensure that the software released into production is of high quality and stable. Additionally, it’s essential to have a robust rollback strategy in case any issues arise after deployment.

Both methods are powerful software development practices that help teams deliver high-quality software to their end users quickly and efficiently. Continuous delivery balances automation and human control, while continuous deployment takes automation to the next level by removing human intervention from the release process. Both require a high degree of discipline, quality assurance, and collaboration between teams to succeed.

While continuous delivery and continuous deployment share some similarities, there are some key differences between the two:

Deployment process: Continuous delivery involves continuously building, testing, and preparing code for release to production but leaving the decision of when to release in the hands of a human. In contrast, continuous deployment automates the entire deployment process, pushing code changes to production as soon as they pass automated tests and validations. With CD, every code change that passes the automated tests is automatically deployed to production without any human intervention.

Level of automation: CD requires a high level of automation and tooling to automate the entire deployment process. This includes setting up the necessary infrastructure, such as deployment pipelines, configuration management, and automated testing, to ensure that the code changes are deployed to production quickly and efficiently. In comparison, CD requires less automation and tooling, as it focuses on preparing the code for release to production but still relies on human intervention to decide when to release the code changes.

Level of risk: Because CD automates the entire deployment process, there is a higher risk of introducing bugs or issues into production, especially if the testing and validation processes are not robust enough. This risk is reduced in continuous delivery because human intervention allows for additional checks and balances, ensuring that the code changes are thoroughly tested and validated before they are released to production.

Business requirements: Continuous deployment may not be suitable for all businesses or industries. Some organizations may have strict compliance requirements, governance policies, or other regulatory constraints that require a higher degree of oversight and control over the release process. Continuous delivery offers the flexibility to accommodate these requirements by allowing for human intervention and decision-making in the release process.

As a result, CD and CD differ primarily in the degree of automation and control over the deployment process. CD automates the entire deployment process, while CD focuses on preparing the code for release but leaves the decision to release in the hands of a human. Both practices are important for efficient and reliable software delivery, and the choice of which to use depends on the business requirements and the risk tolerance of the organization.

HOW TO IMPLEMENT CONTINUOUS DELIVERY IN SOFTWARE DEVELOPMENT?

Continuous delivery is a software development approach focusing on building, testing, and releasing software frequently and in small increments. The goal is to minimize the time between writing code and to deliver it to customers while ensuring high quality and stability. Here are the steps to implement continuous delivery:

1. Automate the build process: The first step is to automate the build process so that every code change triggers an automated build and test process. This ensures that all changes are integrated and tested as soon as possible, catching bugs and errors early in the development process.
2. Adopt continuous integration: Continuous integration involves merging all code changes into a shared repository several times a day. This ensures that all code changes are regularly integrated and tested, reducing the risk of integration issues and conflicts.
3. Use automated testing: Automated testing helps to ensure that software is delivered with high quality and that it meets customer requirements. This includes unit testing, integration testing, end-to-end testing, and automated performance and security testing.
4. Implement continuous deployment: Continuous deployment involves deploying code changes automatically to production as soon as they pass all tests. This ensures that the code is always deployable, reducing the time and risk associated with manual deployments.
5. Monitor and measure: Continuous delivery requires continuous monitoring and measuring of the software delivery process, including performance, quality, and customer feedback. This allows for continuous improvement and optimization of the delivery process.
6. Embrace a DevOps culture: Finally, implementing continuous delivery requires a cultural shift towards collaboration and automation between development and operations teams. This includes adopting DevOps practices and tools, such as infrastructure as code, monitoring and logging, and automated deployment.

By following these steps, organizations can implement continuous delivery and deliver high-quality software faster and more efficiently. It goes without saying, but the basics are important when you are first setting up a transition to CD.

• You need to evaluate what it will take, as well as review overall strategies and stakeholders’ goals.
• Next, draw up a schedule of builds and maintenance release cycles; review builds’ dependency management; and identify any gaps in technologies, tools, and processes.
• The next major phase involves CI and further defining the process. Develop a CI workflow and document the design flow. It should contain branching strategies, merging strategies, dependencies, and multi-site coordination.
• Choose CI technologies and tools.
• Determine and document the timing for automation.

By implementing continuous delivery, you can reduce the time and effort required to release software updates, increase the quality of the codebase, and ensure that the software can be reliably released to production at any time.

CONTINUOUS DELIVERY TOOLS

Continuous delivery is a software development approach in which code changes are frequently and automatically built, tested, and deployed to production. To achieve this, there are several tools that can be used in the CD pipeline, including:

Continuous Integration (CI) tools: These tools are used to build, test, and validate code changes automatically as soon as they are checked into version control. CI tools can run automated tests, run static code analysis, and generate reports to provide quick feedback on the quality of code changes. Some popular CI tools are:

• Jenkins: An open-source automation server that supports continuous integration and delivery. Jenkins has a large plugin ecosystem and can integrate with the most popular tools.
• Travis CI: A cloud-based continuous integration and delivery platform that provides native support for several programming languages.
• CircleCI: Another cloud-based CI/CD platform that supports many programming languages and frameworks.

Source code management (SCM) tools: These tools are used to manage the versioning of source code, track changes, and collaborate on code changes among teams. SCM tools also help developers roll back changes when needed. The most popular SCM tool is Git, but other tools include:

• Git: A popular open-source version control system (VCS) that manages source code and other files for software development projects.
• Subversion (SVN): A centralized version control system that tracks changes to files and directories.
• Mercurial (Hg): A distributed version control system that supports branching and merging.

Configuration management tools: These tools are used to automate the deployment and management of infrastructure and applications. Configuration management tools can automate repetitive tasks, such as provisioning servers, configuring databases, and deploying applications. Popular configuration management tools include:

• Ansible: A simple automation language that can automate applications, networks, and infrastructure.
• Puppet: An open-source configuration management tool that automates the management of infrastructure.
• Chef: A configuration management tool that uses a domain-specific language (DSL) to manage infrastructure.

Test automation tools: These tools are used to automate the testing of applications and help ensure that code changes do not introduce defects or break existing functionality. Test automation tools can run unit tests, functional tests, and integration tests. Popular test automation tools include:

• Selenium: A tool for automating web browsers and testing web applications.
• JUnit: A unit testing framework for Java.
• TestNG: A testing framework for Java that supports parallel execution and test dependencies.

Containerization and orchestration tools: These tools are used for packaging and deploying applications in containers and managing their deployment across multiple environments. Containerization and orchestration tools can help ensure that applications are portable and can run on any infrastructure. Popular containerization and orchestration tools include:

• Docker: A platform for building, shipping, and running containers.
• Kubernetes: An open-source container orchestration platform that automates the deployment, scaling, and management of containerized applications.
• Mesos: An open-source cluster manager that can run multiple frameworks, including Docker, Hadoop, and Apache Spark.

Monitoring and logging tools: These tools are used to monitor the performance and health of applications in production and provide insights into potential issues. Monitoring and logging tools can help developers and operations teams quickly identify and fix issues. Popular monitoring and logging tools include:

• Prometheus: An open-source monitoring system that collects metrics and alerts on abnormal conditions.
• Grafana: A popular open-source platform for visualizing and analyzing data from multiple sources, including Prometheus.
• ELK Stack: A collection of three open-source tools (Elasticsearch, Logstash, and Kibana) used for log management and analysis.

Overall, a combination of these tools is used in the CD pipeline to automate the building, testing, deployment, and monitoring of software applications.

CONCLUSION

Continuous delivery helps organizations to be more responsive to customer needs, deliver software faster, and minimize the risk of errors and downtime. By using automated testing and deployment tools, continuous delivery enables teams to reduce the time and effort required to release software, freeing up more time for innovation and experimentation.

Overall, continuous delivery is a critical aspect of modern software development that enables teams to respond quickly to changing market needs, and deliver software that meets customer requirements. While it requires a significant investment in infrastructure and automation tools, the benefits of continuous delivery in terms of speed, efficiency, and quality make it a worthwhile investment for any organization looking to stay ahead of the competition in today’s fast-paced digital world.